Patent GB-421466-A (GB)
Title: Improvements relating to the resisting of alkaline dyeing liquors
IPC: D06P5/12
Filed: 1933-03-21
Abstract: Printing, resist.--Coloured resist effects are obtained upon fabrics dyed with the use of an alkaline dyeing liquor by applying to selected areas a printing paste containing dye material and a thickener precipitable by alkali with the production of a semi-permeable membrane but free from ingredients which would react to any substantial extent with constituents of a dyeing liquor subsequently to be applied and thereafter subjecting the printed fabric to an alkaline dyeing liquor.  Specified thickeners are gum arabic, gum senegal, locust bean mucilage and water-soluble methyl cellulose.  To assist the membrane formation a small amount of a metal salt, such as aluminium acetate, manganese chloride or copper sulphate, yielding a water-insoluble hydroxide with the alkali, may be incorporated in the printing paste and the dyeing liquor may contain agents such as sodium oleate, trisodium phosphate or sodium ferrocyanide capable of precipitation or absorption upon the constituents of the resist. The dye material in the resist may be a vat dye, a leuco ester thereof, a basic dye, a substantive alkali-soluble passive component or a substantive sulphur dye.  The paste may also contain a dispersing agent such as sodium benzylsulphanilate, an ester such as monoacetin, a wetting agent, such as Prestabitol V, and, if required, an oxidizing agent, such as sodium chlorate, incapable of decomposing the reducing agent of a vat dye composition.  The alkaline dyeing liquor may contain a dyestuff, such as Indanthrene blue GCD or a component, such as Naphthol AS/LB. The formation of the dyes from the azo coupling components is completed by development with a diazotized component.  The following examples are specified.  (1) An aqueous paste containing Naphthol AS/OL, soda oleine, manganese chloride and Colloreseine thickening is printed upon a fabric of regenerated cellulose and the printed goods are padded in a solution containing Naphthol AS/LB, Naphthol AS/SG, soda oleine, sodium oleate and caustic soda, dried, passed through a solution containing 1--5 per cent of caustic soda at 120--130 DEG F., rinsed in cold water, developed with diazotized Fast red RL base, rinsed and soaped to obtain a red resist upon a brown ground.  (2) A paste containing Naphthol AS/SW, soda oleine, manganese chloride, Colloreseine and locust bean thickening is printed upon a mercerized cotton fabric and the printed goods are padded in a solution containing Caledon blue GCD, re-vatted for 30 seconds at 140 DEG  F. in an alkaline hydrosulphite solution, rinsed in cold water containing hydrogen peroxide, developed with diazotized Fast scarlet R base and rinsed in soap solution to obtain a red resist upon a blue ground.  (3) A paste containing Soledon brilliant purple RR, Colloreseine and locust bean thickening, sodium chlorate, manganese chloride, ammonium thiocyanate and triacetin is printed upon a cotton or silk fabric and the printed goods are aged, padded in a solution containing Caledon jade green X200, caustic soda, sodium hydrosulphite and sodium oleate, passed, directly or after drying, into a solution of sodium perborate, rinsed, treated with a hot solution of oxalic acid, soaped and dried.  (4) A cotton or silk fabric, printed and aged as in (3) is padded in a solution containing Naphthol AS/G, sodium oleate and caustic soda, dried, developed with diazotized 2:5-dichloraniline, washed in a hot solution of oxalic acid and boiled in soap solution to obtain a violet resist upon a fast lemon ground.  Specifications 386,365 and 405,005 are referred to.  The Provisional Specification refers also to Specification 393,381.